In surface acoustic wave (SAW) devices, reflections from the edges of the propagation plane must be suppressed to prevent distortion of the signal. Where the SAW device is designed for application in the 50-300 MHz range, it is known that the edge reflections of surface acoustic waves can easily be absorbed, suppressed or attenuated by applying a liquid (e.g. water), wax, (See Richardson et al., Applied Physics Letters 16, 2 pp. 82-84 (1970)), a masking tape, adhesive tape or scotch tape or glue to the edges of the SAW device. For a discussion of elastic surface waves, see Dransfeld et al., Physical Acoustics, Vol. 7, pp. 219-272, particularly 235, 259-263, Academic Press, New York, 1970. SAW devices operating at a lower frequency are being studied for application as a frequency discriminator and as an IF filter in the IF circuit of FM receivers. At this lower frequency, i.e. 10.7 MHz, the absorption of the surface acoustic waves by the above materials is inadequate. It is desirable to provide more suitable materials for attenuating the edge reflections of a surface acoustic wave device. The present invention provides such materials.